1. Field of the Invention
This invention relates to agricultural equipment and, more particularly, to a mechanism for repositioning implements, as to adjust the height thereof relative to a towable mounting frame.
2. Background Art
It is common to utilize gang mounted agricultural implements to continuously treat a substantial width of a field behind a towing vehicle. The implements may take any of a number of different forms. For example, the implements can be residue mulchers or resituators, cultivators, planters, fertilizers, etc. It is also known to provide a height adjustment capability for the individual implements. This feature accommodates different terrains and allows the user to alter soil working depth. Because the implements and associated frame are quite bulky and heavy, it is normally impractical to resituate any substantial number of the implements simultaneously. Consequently, designers have been mounting such implements to be individually repositionable. Examples of exemplary prior art structures are seen in U.S. Pat. No. 353,491 to Hepworth et al, and U.S. Pat. No. 2,925,872, to Darnell.
John Deere currently manufactures a mechanism for repositioning an agricultural implement which employs an adjusting rod that is rotatable to individually raise and lower implements. An operating handle is provided on the top of the rod and is grasped and turned to rotate the adjusting rod to thereby raise and lower the associated implement.
One difficulty with this structure is that it does not lend itself to automated operation. Instead, the user must grasp and manually turn the operating handle for each individual implement. Not only is this inconvenient and time consuming, but inevitably the user's hands and arms fatigue, particularly in certain equipment which may employ dozens of such individual implements.
Another problem with the prior art structures resides in the particular configuration of the operating handle. One such operating handle, which is described in greater detail below, is molded from plastic and has an inverted, cup-shaped configuration. The open end of the operating handle is placed over the top of the adjusting rod. The adjusting rod has a pin thereon which is guided into a control slot on the operating handle. Once the operating handle is in its operative position on the operating rod, a U-shaped wire clip is directed radially through the body of the operating handle to thereby prevent inadvertent withdrawal of the pin from the slot in the operating handle.
This particular construction has a number of drawbacks. First of all, while manufacture from plastic is economical, the plastic is prone to cracking and being stripped by the pin on the adjusting rod.
A further problem is that the wire clip is relatively difficult to seat in its locked position. The user must direct the free ends of the legs through holes on one side of the handle into and through aligned holes at a diametrically opposite location. The user may have difficulty aligning the clip to effect assembly thereof. The clip may be dropped and lost during the assembly process. Further, the wire clip is relatively thin and prone to rusting, corrosion from chemicals, and breakage. Still further, the clip may work itself loose under the vibrations normally encountered in the operating environment, which would then free the operating handle from the adjusting rod.